Terminology
Massless packet of energy that can travel at the speed of light
What is kVp
Speed of electrons
What is collimation
Restriction in size and shape of beam to reduce exposure
If anatomy is too light…. If it’s too dark…..
KVP too low, kVp too high
What radiographic system requires a plate reader
Computed radiography
Define cathode and anode
What is Bremsstrahlung
most X-rays see this, electrons slow as they pass nucleus and give up energy
The three fates of a photon are…
Straight from anode to imaging plate
stops and makes white area
compton effect or scatter
5 radiographic opacities
Metal, mineral, soft tissue, fat, gas
What radiographic system has the fastest processing
digital
Photoelectric effect vs compton
X-ray photon completely attenuated and makes contrast
scatter
What is characteristic radiation
Electron ejects inner shell electron and an outer shell electron drops in. Energy given up is photon
How does dna damage occur
Indirect action from the action of free radicals created from adjacent water molecules
Summation vs silhouette
Superimposition, summing up overlapping tissues
structures of same opacity touching each other
What kind of waves does ultrasound use
Sound waves of very high frequency
Distance between X-ray tube and film of image receptor is called the…
Focal film distance
How is an x ray image created
Differences in photon attenuation based on the energy of the X-ray, tissue thickness, physical density, atomic number Z of tissue
Ultrasound is non… and. Non…
Invasive and ionizing
X rays are what kind of radiation
Ionizing
What depth or tissue is higher frequency ultrasound used for
Superficial
As kVp decreases
As kVp decreases contrast increases and less scatter
What setting affects the number of photons? The energy of photons?
mA and kVp
As kVp increases…
Contrast decreases and more scatter
All soft tissue in the body has the same…
average Z or physical density
Direct vs indirect radiography difference
A step about light in indirect